Sam McBride: In the absence of humility, First Minister's position is increasingly precarious

That she has done so when the consequences of that dysfunctionality on her watch as minister are catastrophic losses to the public purse which will impact on health and education spending over the next two decades is indicative of extreme desperation.

Although in her speech to the Assembly last week Mrs Foster made a limited expression of regret for what had happened, her consistent line of defence has been to place all of the blame at the feet of her officials.

As more and more evidence of Mrs Foster’s awareness of the RHI scheme has emerged, that improbable argument, coupled with a striking lack of the sort of public contrition which is part of the textbook response from a politician to a crisis, appears to have led to many people leapfrogging the potential charge of incompetence and instantly settling on the belief that there was corruption, if not on Mrs Foster’s part, then on the part of someone in the DUP.

The truth is that not a scintilla of evidence points in that direction. What we have seen to date is evidence of exceptionally incurious behaviour by civil servants, by Mrs Foster, by her special adviser (her hand-picked aide who is paid £85,000 a year to give her expert advice) and by her successor Jonathan Bell.

Then, having presided over one disaster, those people had various roles in the unhasting approach to closing the scheme once the problem was inescapably obvious and it was careening wildly out of control.

Based on what has emerged so far, it appears clear that several civil servants were seriously negligent. The failure of the civil service to discipline a single official for what has gone on is extraordinary and ultimately it for civil servants’ political masters – the DUP and Sinn Fein – to ensure that publicly paid officials who are given generous benefit packages are accountable for actions which, from what we know thus far, reek of incompetency.

The fact that not a single civil servant insisted on a ‘ministerial direction’ - the nuclear option which is used a handful of times each year at Stormont when officials have serious concerns about a policy and formally absolve themselves of blame – leaves officials seriously exposed in this affair.

And yet, even if the most culpable individuals here are officials (and that is not yet clear), it is unseemly for any minister to entirely blame underlings.

An honourable general who loses a battle through no fault of his own still tenders his resignation; a conscientious football manager whose team is knocked out of the World Cup accepts the blame even if his players let him down; a newspaper editor appears in court to defend what ran in his newspaper even if far more junior staff were response for a serious error.

The lack of anything approaching humility in how Mrs Foster has handled this crisis suggests that she believes her career will be ended if she accepts any responsibility whatsoever for this catastrophe, such is the scale of the public fury over what is – at best – waste of their money.

She may be right in that assumption – although often the public reward, rather than chastise, politicians who admit to human failure.

But her strategy thus far has been utterly counterproductive.

The opposition of the DUP to a full public inquiry into the affair adds to the sense that the party has something to hide in all of this – even if the party bears minimal fault for the debacle.

It is still likely that Mrs Foster, who went into this crisis with almost unprecedented levels of political capital, will survive.

But with each week since the BBC Spotlight programme precipitated this extraordinary situation her position is becoming more and more vulnerable.

Sinn Fein is not yet going for the jugular, and Martin McGuinness has serious health problems with which to contend.

But if Sinn Fein gives the DUP an ultimatum – replace Mrs Foster temporarily or face an angry electorate in a snap election – the DUP may decided that Mrs Foster should be sacrificed for the greater good of them all.